Drug development
Open Door - May 2007 page 10
The development of new drugs is a long and difficult process. Fewer than one or two compounds in 10,000 tested actually make it through to being licensed treatments. A potential new medicine may be rejected at any point in the development process on safety, efficacy or quality grounds. On average it will take10- 15 years for a new compound to get from the test tube into the medicine cabinet.
Discovery
Many thousands of new chemical compounds will be created and tested to identify those that have potential. These go into a pre-clinical phase of laboratory and animal testing before being given a clinical trials authorisation that allows them to be tested in humans. There is a very high drop out rate at this stage; less than 1% of all the compounds that are made ever progress to testing in humans.
Once permission has been given for a compound to be tested in humans, it goes through three different clinical testing phases.
Phase I
The first step in testing a new drug is to determine its safety in a small number of healthy volunteers. This stage helps researchers understand some aspects of how it works and establishes the likely dose required.
Phase II
If the treatment proves to be safe, studies begin to determine the effectiveness of the drug in people with the condition to be treated. These studies may last several months or years and involve larger numbers of people, perhaps one or two hundred. The study is 'controlled' - that is the drug is compared with the standard treatment or placebo (dummy treatment), 'double-blind' - that is neither the investigators nor the participants know which treatment they are receiving, and 'randomised' - that is participants will be randomly allocated to receive active treatment or placebo.
Phase III
If a drug shows effectiveness, a larger study is conducted in hundreds of people. These clinical trials may be conducted at different locations (multi-centre) and across several countries and may last several years. These studies allow researchers to more accurately assess the potential of the new drug in a wider range of people and compare it to existing treatments
Regulation of new drugs
Data from all of these phases is presented to the regulatory authorities (in the UK this is the MHRA - Medicines and Healthcare products Regulatory Agency or the EMEA - European Medicines Agency). If the authorities are satisfied that the new medicine is effective, safe and meets manufacturing quality standards, a marketing authorisation or licence is issued.
Once a new medicine has been licensed, there may still be one final hurdle. Set up to help eliminate post code lottery prescribing, NICE (National Institute for Health and Clinical Excellence) for England and Wales and the SMC (Scottish Medicines Consortium) for Scotland appraise certain new medicines and will look at issues such as cost effectiveness of the new treatment.
Once the newly-licensed medicine is in general use it will be carefully monitored for safety. Rare side effects, for example those occurring in 1 in 10,000, may only become apparent at this stage.
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